Indirect reading inside caliper

Abstract

An improved indirect reading inside caliper which eliminates the need for a plurality of telescoping inside gauges, the inside caliper comprising an elongated body, a pair of measuring fingers and a bracket slidable on the body, respective manually operated fasteners for the fingers and bracket for holding the same in selected positions on the body, one of the fingers and the bracket fastened together so that they slide in unison on the body, a compression spring in the interior of the body operative upon the bracket so as to yieldably urge it toward one end of the body, a manual adjustment associated with the bracket for imparting incremental movement to the one finger relative to the other finger, whereby a range of inside diameters of apertures having size ratios of the order of 1 to 10 may be precisely measured, the body having an axially extending slot therein extending substantially end to end thereof to maximize the maximum distance of travel between the fingers, the slot being V-shaped, each fastener having V-shaped shoulders thereon which engage the slot, whereby to circumferentially align said fingers and bracket on the body, the fastener for the bracket having an inner end which extends into the interior of the body for engaging an end of the compression spring, respective protuberances on corresponding outside faces of the fingers, and the fingers having opposing inside faces thereon ground flat so as to minimize the minimum distance between the protuberances.

What I claim is: 
     
       1. An improved indirect reading inside caliper which eliminates the need for a plurality of telescoping inside gauges, said inside caliper comprising an elongated hollow tubular body, a pair of measuring fingers and a bracket slidable on said hollow tubular body, respective manually operated fasteners for said fingers and bracket for holding the same in selected positions on said hollow tubular body, means fastening one of said fingers and said bracket together so that they slide in unison on said hollow body, a compression spring in the interior of said hollow body operative upon said bracket so as to yieldably urge it toward one end of said hollow body, and manual adjustment means associated with said bracket for imparting incremental movement to said one fingers relative to the other finger, whereby a range of inside diameters of apertures having size ratios of the order of 1 to 10 may be precisely measured, said hollow tubular body having an axially extending slot therein extending substantially end to end thereof to maximize the maximum distance of travel between said fingers, said slot being V-shaped, each of said fasteners having V-shaped shoulders thereon which engage said slot, whereby to circumferentially align said fingers and bracket on said hollow tubular body, the fastener for said bracket having an inner end which extends into the interior of said tubular body for engaging an end of said compression spring, and said fingers having respective protuberances on corresponding outside faces thereof, and said fingers having opposing inside faces thereon ground flat so as to minimize the minimum distance between said protuberances.